Ukraine said it attacked Rosneft PJSC’s Syzran refinery and a small port on Russia’s Azov Sea coast, adding to spate of recent strikes that are becoming costly for Moscow and the country’s oil industry.

Ukraine’s military forces struck the oil-processing facility in Russia’s Volga region overnight, its General Staff said on Telegram, adding the refinery had been supplying fuel to the Kremlin’s army. It has a design capacity of 8.5 million barrels per year — about 170,000 barrels per day — and has been attacked several times this year, most recently in August.

Earlier strikes on Rosneft’s Saratov refinery, also in the Volga region, halted the facility’s primary-processing altogether as of early December, Ukraine’s General Staff said. The facility has a design capacity of around 140,000 barrels per day, and was last attacked on Nov. 28.

Bloomberg could not independently verify the claims, and Rosneft didn’t immediately respond to a request for comment.

The latest attacks follow a record number of Ukrainian drone strikes on Russian refineries in November. Russia’s military has also continued regular attacks on Ukrainian energy infrastructure and civilian targets, including housing, in a bid to undermine morale heading into winter.

Amid the mutual attacks, US President Donald Trump has been pushing for a truce between Russia and Ukraine. A recent series of talks over a 28-point peace proposal have so far been inconclusive, even though the Kremlin said earlier this week that President Vladimir Putin had “very useful” talks with US envoy Steve Witkoff and Trump’s son-in-law Jared Kushner.

Early Friday morning, Ukraine’s military also struck the Temryuk port on Russia’s Azov Sea coast, the General Staff said. The port has terminals for loading grain, chemical and general cargoes, as well as oil products. The capacity of the oil-product terminal is as much as 3,000 tons per day, according to the facility’s website. That’s equivalent to around 20,000 barrels a day.

Ukraine has intensified attacks on the port infrastructure in Russia’s south in the recent weeks. The attacks have resulted in temporary halts to loadings at the key Novorossiysk terminal on the Black Sea and, most recently, halved flows of the widely traded CPC grade of crude. About 90% of that oil comes from Kazakhstan, not Russia.

Putin responded with a warning that Moscow may consider striking the ships of countries supporting Ukraine if the attacks don’t halt.